Instr Loop Check

DO C. NO .

M S - P RO C- I N- 001

METHOD STATEMENT

TITLE

9. INSTRUMENT LOOP CHECK 

PAGE

1

OF 3

9.1 9. 1 GENERAL

Loop Test shall be carried out according according to PQP-017-012 Rev. 1 pages 35, 36, 37 of  42. 42 .

The Construction Contractor and Client should witness the loop check. All results shall be recorded on Loop Check Sheet.

A GREEN color sticker shall a ffix all i nstruments completed during loop checking.

The following data shall be inspected prior for loop checking. The Tag no. of instrument The Engineering Unit configured on DCS The Range of the instrument The DCS Tag of instrument

The Loop Check Sheet shall consist of; Data Sheet, P & ID, Set Point List, Bench Certificate, and Instrument Loop Diagram.

DOC. NO.

MS-PROC-IN-001

METHOD STATEMENT

TITLE

9. INSTRUMENT LOOP CHECK 

PAGE

2

OF 3

9.2 LOOP CHECK 

9.2.1 Flow Loop

1. The instrument shall be tested at 0%, 50% and 100% of full scale shall be verified on DCS at the time, both for upscale and down scale signal variation. 2. The signal simulation shall be done using Honeywell SFC. 3. Record the results on the Loop Check Sheet. 4. If the flow loop consist of control valve, loop shall be tested as complete loop the direction of control valve shall be inspected and should meet with the process requirement. 5. Fix the Green sticker after successful testing.

9.2.2

Pressure / Vacuum Loop

1. The instrument shall be tested at 0%, 50% and 100% of full scale shall be verified on DCS at the time, both for upscale and down scale signal variation. 2. The signal simulation shall be done using Honeywell SFC. 3. Record the results on the Loop Check Sheet. 4. If the flow loop consist of control valve, loop shall be tested as complete loop the direction of control valve shall be inspected and should meet with the process requirement. 5. Fix the Green sticker after successful testing.

9.2.3

Level Loop

1. The instrument shall be tested at 0%, 50% and 100% of full scale shall be verified on DCS at the time, both for upscale and down scale signal variation. 2. The signal simulation shall be done using Honeywell SFC. 3. Record the results on the Loop Check Sheet. 4. If the flow loop consist of control valve, loop shall be tested as complete loop the direction of control valve shall be inspected and should meet with the process requirement. 5. Fix the Green sticker after successful testing.

DOC. NO.

MS-PROC-IN-001

METHOD STATEMENT

TITLE

9.2.4

9. INSTRUMENT LOOP CHECK 

PAGE

3

OF 3

Temperature Loop

1. The instrument shall be tested at 0%, 50% and 100% of full scale shall be verified on DCS at the time, both for upscale and down scale signal variation. 2. The signal simulation shall be done using Honeywell SFC. 3. Record the results on the Loop Check Sheet. 4. If the flow loop consist of control valve, loop shall be tested as complete loop the direction of control valve shall be inspected and should meet with the process requirement. 5. Fix the Green sticker after successful testing.

9 .2 .5

Sw it chi ng L oo p

1. The loop can be test by giving open or close signals at the terminal of the instruments. 2. Alarms on the DCS or the annunciator console shall be confirmed. 3. Record the results on the Loop Check Sheet. 4. Fix the GREEN sticker after successful testing.

9 .2 .6

Co nt rol V al ve s

1. The valves shall be stroke tested by putting the DCS on MANUAL Mode and simulating 0%, 50% and 100% upscale and downscale. 2. The indication of the valve shall be witnessed on the field. 3. Record the results on the Loop Check Sheet. 4. Fix GREEN sticker after successful testing.

9. 2. 7

On-Off Val ve

1. Check the action of the valve by giving signal from the DCS, PLC and Interlock  system. 2. Check the solenoid action, limit switch action and record the results on the Loop Check Sheet. 3. Fix the GREEN sticker after successful testing.